Production of diesel and base stocks from crude oil

ABSTRACT

A process of producing Group III base oils, along with a naphtha product and diesel product, from whole waxy crude oil is provided. The inventive process omits the typical vacuum distillation stage and separations to form the typical cuts off of the vacuum tower. By selecting a waxy crude oil suitable for processing without separations, the crude oil may be hydroprocessed, dearomatized, dewaxed, and hydrofinished to produce a Group III base oil. Additionally, the dewaxing catalyst will isomerize the naphtha range molecules to increase the octane value to a suitable level for blending into gasoline and the diesel range molecules to reduce the diesel cloud point.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/516,312, filed on Jun. 7, 2017, the entire contents of which areincorporated herein by reference.

FIELD

Systems and methods are provided for production of diesel and lubricantoil base stocks from waxy whole crude oil.

BACKGROUND

Crude petroleum may be distilled and fractionated into many productssuch as gasoline, kerosene, jet fuel, asphaltenes, and the like. Oneportion of the crude petroleum form the base of lubricating base oilsused in, inter alia, the lubricating of internal combustion engines.Lube oil users are demanding ever increasing base oil quality, andrefiners are finding that their available equipment is becoming less andless able to produce base oils that meet these higher qualityspecifications. New processes are required to provide refiners with thetools for preparing high quality modern base oils, particularly usingexisting equipment at lower cost and with safer operation.

Finished lubricants used for such things as automobiles, diesel engines,and industrial applications generally are comprised of a lube base oiland additives. In general, a few lube base oils are used to produce awide variety of finished lubricants by varying the mixtures ofindividual lube base oils and individual additives. Typically, lube baseoils are simply hydrocarbons prepared from petroleum or other sources.Lube base oils are normally manufactured by making narrow cuts of vacuumgas oils from a crude vacuum tower. The cut points are set to controlthe final viscosity and flash point of the lube base oil.

Group I base oils, those with greater than 300 ppm sulfur and 10 wt %aromatics, are generally produced by first extracting a vacuum gas oil(or waxy distillate) with a polar solvent, such as N-methyl-pyyrolidone,furfural, or phenol. The resulting waxy raffinates produced from solventextraction processes are then dewaxed, either catalytically with the useof a dewaxing catalyst such as ZSM-5, or by solvent dewaxing. Theresultant base oil may be hydrofinished to improve color and otherlubricant properties.

Group II base oils, those with less than 300 ppm sulfur and 10 wt %aromatics, and with a viscosity index range of 8-120, are typicallyproduced by hydrocracking followed by selective catalytic dewaxing andhydrofinishing. Hydrocracking upgrades the viscosity index of theentrained oil in the feedstock by ring cracking and aromaticssaturation. The degree of aromatics saturation is limited by the hightemperature (300-450° C.) of the hydrocracking stage. In the secondstage of the process, the hydrocracked oil is dewaxed, either by solventdewaxing or by catalytic dewaxing, with catalytic dewaxing typicallybeing the preferred method. The dewaxed oil is then preferablyhydrofinished at mild temperatures (150-300° C.) to remove polynucleararomatics (PNAs) which were not converted in the first stage and thedewaxing stage and which have a strongly detrimental impact on lube baseoil quality.

Group III base oils have the same sulfur and aromatics specifications asGroup II base stocks but have viscosity indices above 120. Thesematerials are manufactured with the same type of catalytic technologyemployed to produce Group II base oils but with either the hydrocrackerbeing operated at higher severity, or with the use of feedstocks withhigher wax content.

A typical lube hydroprocessing plant consists of two primary processingstages. In the lead stage, a feedstock, typically a vacuum gas oil,deasphalted oil, processed gas oils, or any combination of thesematerials, is hydrocracked. In a second stage, the hydrocracked oil isdearomatized, preferably with an aromatic saturation catalyst, anddewaxed, preferably with the use of a highly shape-selective catalystcapable of wax conversion by isomerization. The dewaxed, dearomatizedoil can be subsequently hydrofinished to remove PNA impurities.Operation of the final hydrofinishing step is optimized to convert PNAimpurities since significant conversion of one ring and two ringaromatics cannot be accomplished in the final hydrofinishing stepbecause of its low operating temperature.

It is desirable to continue to improve the process of producing baseoils, particularly Group III base oils with the more stringentspecifications, by minimizing the required processing stages andseparations required.

SUMMARY

The claimed invention provides a process of producing Group III baseoils, along with a naphtha product and diesel product, from whole waxycrude oil without the typical vacuum distillation stage and separationsto form the typical cuts off of the vacuum tower. By selecting a waxycrude oil suitable for processing without separations, the crude oil maybe hydroprocessed, dearomatized, dewaxed, and hydrofinished to produce aGroup III base oil. Additionally, the dewaxing catalyst will isomerizethe naphtha range molecules to increase the octane value to a suitablelevel for blending into gasoline and the diesel range molecules toreduce the diesel cloud point.

In one embodiment, a method for producing lubricant base oils from awhole petroleum crude oil is provided. A whole petroleum crude oilfeedstock comprising less than about 2 wt % of heptane asphaltenes, lessthan about 2 wt % of Conradson carbon residue (CCR), and less than about50 ppm of metals is hydrotreated over at least one bed of ahydrotreating catalyst under effective hydrotreating conditions toproduce a hydrotreated effluent having less sulfur, nitrogen andaromatics than the whole petroleum crude oil. The hydrotreated effluentis then dewaxed in the presence of a dewaxing catalyst to produce anaphtha product having an octane value greater than 60, a diesel producthaving a cloud point less than 0° C., and a lubricant base oil product,which is fractionated into at least a low viscosity lubricant base oilproduct having a viscosity of 2-8 cSt at 100° C. and a high viscositylubricant base oil product having a viscosity of 6-30 cSt at 100° C.

In another embodiment, a naphtha product, a diesel product, and alubricant base oil product is produced from a whole petroleum crude oil.A whole petroleum crude oil feedstock, containing less than about 2 wt %of heptane asphaltenes, less than about 2 wt % of Conradson carbonresidue (CCR), and less than about 50 ppm of metals, is provided,without separation or pretreatment, to a hydrotreating unit, where it ishydrotreated over at least one bed of a hydrotreating catalyst undereffective hydrotreating conditions to produce a hydrotreated effluenthaving less than 15 ppm sulfur, less than 5 ppm nitrogen, less than 2 wt% C3- paraffins, and less than 25 wt % of aromatics. The hydrotreatedeffluent is dewaxed in the presence of a dewaxing catalyst to produce adewaxed effluent, which is separated into at least a naphtha producthaving an octane value greater than 60, a diesel product having a cloudpoint less than 0° C., and a base stock product. The base stock productis subjected to hydrofinishing and/or aromatic saturation to removepolynuclear aromatic compounds and produce a hydrofinished base stock,which is then fractionated into at least a low viscosity lubricant baseoil product having a viscosity of 2-8 cSt at 100° C. and a highviscosity lubricant base oil product having a viscosity of 6-30 cSt at100° C.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically shows an example of a configuration suitable forprocessing a whole waxy crude oil feed to form lubricant base oils.

DETAILED DESCRIPTION

All numerical values within the detailed description and the claimsherein are modified by “about” or “approximately” the indicated value,and take into account experimental error and variations that would beexpected by a person having ordinary skill in the art.

Overview

In various embodiments, methods are provided for producing lubricantbase oils from crude oil. In a typical lubricant base oil productionprocess, crude oil is subjected to atmospheric distillation to obtain adistillate cut and an atmospheric residual cut. The atmospheric residualcut is then sent to vacuum distillation where at least volatiledistillate, light neutral distillate, heavy neutral distillate, andvacuum residual cuts are obtained. Deasphalting is then performed on thevacuum residual cut to remove asphaltenes, and the deasphalted oil isthen subjected, along with the light neutral and heavy neutral cuts, tosolvent extraction to remove aromatics. The raffinate from solventextraction may then be hydroprocessed and dewaxed to produce base oils.However, the present inventors have discovered a way to produce highquality lubricant base oils while omitting several steps of the typicalprocess, specifically atmospheric distillation, vacuum distillation,deasphalting and solvent extraction.

FIG. 1 shows an example reactor system 100 for the inventive process. Inone embodiment of the inventive process, a feedstock 102 that meetscertain specifications (detailed below) is subjected in a first stage tohydrotreatment in a hydroprocessing unit 110 to remove sulfur, nitrogenand saturate aromatics. The hydrotreated effluent 112 is then processedin a second stage 120 over a stacked bed of noble metal catalysts. Thetop bed of noble metal hydrogenation catalyst further saturates thearomatics in the hydrotreated effluent 112. The bottom bed contains acatalytic dewaxing catalyst which isomerizes the C₄-C₈ n-paraffins(naphtha range molecules) to high octane iso-paraffins to bring thenaphtha product octane number to greater than 70 so it can be directlyblended into gasoline. The catalytic dewaxing catalyst also isomerizesthe C₉ to 650° F.−(343° C.−) boiling point n-paraffins (diesel rangemolecules) to low pour point iso-paraffins to reduce diesel cloud point,and the 650° F.+(343° C.+) range n-paraffins into low pour point GroupIII lube base stocks. The dewaxed effluent 122 is separated bydistillation in column 130 into a naphtha cut 132, a diesel cut 134 andbase stock cut 136, and the base stock cut 136 is hydrofinished inhydrofinishing unit 140 to remove trace polynuclear aromatics. Thehydrofinished base stock 142 is then stripped to remove lighthydrocarbons and separated in column 150 into two fractions—a lightneutral base stock 152 having a low viscosity, 3-5 cSt (at 100° C.), anda heavy neutral base stock 154 having a high viscosity, 8-15 cSt (at100° C.). Both Group III base stock fractions have a viscosity index ofgreater than 120 and pour point of −15° C. and the cloud point-pourpoint spread is less than 30° C.

Feedstocks

Suitable feedstocks for the present invention include whole petroleumcrude oils that are low in metals and heptane asphaltenes. These wholepetroleum crude oils often contain a high volume of waxy hydrocarbons.Ideally, the feedstock will be suitable for processing withoutseparation.

One way of defining a feedstock is based on the boiling range of thefeed. One option for defining a boiling range is to use an initialboiling point for a feed and/or a final boiling point for a feed.Another option, which in some instances may provide a morerepresentative description of a feed, is to characterize a feed based onthe amount of the feed that boils at one or more temperatures. Forexample, a “T5” boiling point for a feed is defined as the temperatureat which 5 wt % of the feed will boil off. Similarly, a “T50” boilingpoint is a temperature at 50 wt % of the feed will boil. The percentageof a feed that will boil at a given temperature can be determined by themethod specified in ASTM D2887. Whole waxy crudes suitable for theclaimed process include, for example, feeds with an initial boilingpoint of at least 70° F. (21° C.), or at least 100° F. (37° C.), or atleast 125° F. (51° C.).

In some aspects, the content of heptane asphaltenes in the whole crudefeedstock can be less than 2.0 wt %, or less than 1 wt %, or less than0.5 wt %, or less than 0.25 wt %, based on the total weight of thefeedstock. The content of heptane asphaltenes in the 1050° F.+(565° C.+)fraction of the feedstock is less than 5.0 wt %. The feedstock may havea metals content of less than 50 ppm, or less than 20 ppm, or less than15 ppm, or less than 10 ppm, or less than 5 ppm, and a content ofcarbonaceous residue of less than 2.0 wt %, or less than 1.5 wt %, orless than 1.0 wt %, or less than 0.5 wt %, as measured by the microcarbon residue test defined in ASTM D4530.

Hydrotreatment Process

The feedstock 102 is hydrotreated in a first stage of the reactor systemby a hydroprocessing unit 110. Hydrotreatment is typically used toreduce the sulfur, nitrogen, and aromatic content of a feed. Thecatalysts used for hydrotreatment of the crude oil can includeconventional hydroprocessing catalysts, such as those that comprise atleast one Group VIII non-noble metal (Columns 8-10 of IUPAC periodictable), preferably Fe, Co, and/or Ni, such as Co and/or Ni; and at leastone Group VI metal (Column 6 of IUPAC periodic table), preferably Moand/or W. Such hydroprocessing catalysts optionally include transitionmetal sulfides that are impregnated or dispersed on a refractory supportor carrier such as alumina and/or silica. The support or carrier itselftypically has no significant/measurable catalytic activity.Substantially carrier- or support-free catalysts, commonly referred toas bulk catalysts, generally have higher volumetric activities thantheir supported counterparts.

The catalysts can either be in bulk form or in supported form. Inaddition to alumina and/or silica, other suitable support/carriermaterials can include, but are not limited to, zeolites, titania,silica-titania, and titania-alumina. Suitable aluminas are porousaluminas such as gamma or eta having average pore sizes from 50 to 200Å, or 75 to 150 Å; a surface area from 100 to 300 m²/g, or 150 to 250m²/g; and a pore volume of from 0.25 to 1.0 cm³/g, or 0.35 to 0.8 cm³/g.More generally, any convenient size, shape, and/or pore sizedistribution for a catalyst suitable for hydrotreatment of a distillate(including lubricant base oil) boiling range feed in a conventionalmanner may be used. It is within the scope of the present disclosurethat more than one type of hydroprocessing catalyst can be used in oneor multiple reaction vessels.

The at least one Group VIII non-noble metal, in oxide form, cantypically be present in an amount ranging from 2 wt % to 40 wt %,preferably from 4 wt % to 15 wt %. The at least one Group VI metal, inoxide form, can typically be present in an amount ranging from 2 wt % to70 wt %, preferably for supported catalysts from 6 wt % to 40 wt % orfrom 10 wt % to 30 wt %. These weight percents are based on the totalweight of the catalyst. Suitable metal catalysts includecobalt/molybdenum (1-10% Co as oxide, 10-40% Mo as oxide),nickel/molybdenum (1-10% Ni as oxide, 10-40% Co as oxide), ornickel/tungsten (1-10% Ni as oxide, 10-40% W as oxide) on alumina,silica, silica-alumina, or titania.

The hydrotreatment is carried out in the presence of hydrogen. Ahydrogen stream is, therefore, fed or injected into a vessel or reactionzone or hydroprocessing zone in which the hydroprocessing catalyst islocated. Hydrogen, which is contained in a hydrogen “treat gas,” isprovided to the reaction zone. Treat gas, as referred to in thisdisclosure, can be either pure hydrogen or a hydrogen-containing gas,which is a gas stream containing hydrogen in an amount that issufficient for the intended reaction(s), optionally including one ormore other gasses (e.g., nitrogen and light hydrocarbons such asmethane), and which will not adversely interfere with or affect eitherthe reactions or the products. Impurities, such as H₂S and NH₃ areundesirable and would typically be removed from the treat gas before itis conducted to the reactor. The treat gas stream introduced into areaction stage will preferably contain at least 50 vol. % and morepreferably at least 75 vol % hydrogen.

Hydrogen can be supplied at a rate of from 100 SCF/B (standard cubicfeet of hydrogen per barrel of feed) (17 Nm³/m³) to 1500 SCF/B (253Nm³/m³). Preferably, the hydrogen is provided in a range of from 200SCF/B (34 Nm³/m³) to 1200 SCF/B (202 Nm³/m³). Hydrogen can be suppliedco-currently with the input feed to the hydrotreatment reactor and/orreaction zone or separately via a separate gas conduit to thehydrotreatment zone.

Hydrotreating conditions can include temperatures of 200° C. to 450° C.,or 315° C. to 425° C., preferably 340° C. to 420° C.; pressures of 250psig (1.8 MPag) to 5000 psig (34.6 MPag) or 300 psig (2.1 MPag) to 3000psig (20.8 MPag), preferably 1500 psig (10.3 MPag) to 2500 psig (13.8MPag), more preferably 1750 psig (12.1 MPag) to 2250 psig (13.1 MPag);liquid hourly space velocities (LHSV) of 0.1 hr⁻¹ to 10 hr⁻¹, preferably0.1 hr⁻¹ to 2 hr⁻¹, more preferably 0.3 hr⁻¹ to 0.7 hr⁻¹; and hydrogentreat rates of 200 SCF/B (35.6 m3/m3) to 10,000 SCF/B (1781 m³/m³), or500 (89 m³/m³) to 10,000 SCF/B (1781 m³/m³).

The hydrotreatment may be carried out in one or more catalyst beds. Inone embodiment, the hydroprocessing unit 110 contains more than onehydrotreatment catalyst beds, in some embodiments, two catalyst beds,and in some embodiments, three catalyst beds. The hydrotreated effluent112 contains less sulfur, nitrogen, and aromatics than the feedstock102. In some embodiments, the hydrotreated effluent 112 will containless than 15 ppm of sulfur, less than 5 ppm of nitrogen, less than 2 wt% of C₃— paraffins, and less than 25 wt % of aromatics.

In addition to or as an alternative to exposing the petrolatum to ahydrotreating catalyst, the petrolatum can be exposed to one or morebeds of hydrocracking catalyst. The hydrocracking conditions can beselected so that the total conversion from all hydrotreating and/orhydrocracking stages is 15 wt % or less, or 10 wt % or less, or 8 wt %or less, as described above.

Hydrocracking catalysts typically contain sulfided base metals on acidicsupports, such as amorphous silica alumina, cracking zeolites such asUSY, or acidified alumina. Often these acidic supports are mixed orbound with other metal oxides such as alumina, titania or silica.Non-limiting examples of metals for hydrocracking catalysts includenickel, nickel-cobalt-molybdenum, cobalt-molybdenum, nickel-tungsten,nickel-molybdenum, and/or nickel-molybdenum-tungsten. Additionally oralternately, hydrocracking catalysts with noble metals can also be used.Non-limiting examples of noble metal catalysts include those based onplatinum and/or palladium. Support materials which may be used for boththe noble and non-noble metal catalysts can comprise a refractory oxidematerial such as alumina, silica, alumina-silica, kieselguhr,diatomaceous earth, magnesia, zirconia, or combinations thereof, withalumina, silica, alumina-silica being the most common (and preferred, inone embodiment).

In various aspects, the conditions selected for hydrocracking can dependon the desired level of conversion, the level of contaminants in theinput feed to the hydrocracking stage, and potentially other factors. Ahydrocracking process can be carried out at temperatures of 550° F.(288° C.) to 840° F. (449° C.), hydrogen partial pressures of from 250psig to 5000 psig (1.8 MPag to 34.6 MPag), liquid hourly spacevelocities of from 0.05 h⁻¹ to 10⁻¹, and hydrogen treat gas rates offrom 35.6 m³/m³ to 1781 m³/m³ (200 SCF/B to 10,000 SCF/B). In otherembodiments, the conditions can include temperatures in the range of600° F. (343° C.) to 815° F. (435° C.), hydrogen partial pressures offrom 500 psig to 3000 psig (3.5 MPag to 20.9 MPag), and hydrogen treatgas rates of from 213 m³/m³ to 1068 m³/m³ (1200 SCF/B to 6000 SCF/B).The LHSV relative to only the hydrocracking catalyst can be from 0.25h⁻¹ to 50 hr⁻¹, such as from 0.5 hr⁻¹ to 20 hr⁻¹, and preferably from1.0 hr⁻¹ to 4.0 h⁻¹.

In some aspects, a high pressure stripper (or another type of separator)can then be used in between the hydrotreatment stage 110 and catalyticdewaxing stage 120 of the reaction system to remove gas phase sulfur andnitrogen contaminants. A separator allows contaminant gases formedduring hydrotreatment (such as H₂S and NH₃) to be removed from thereaction system prior to passing the hydrotreated effluent 112 into alater stage of the reaction system. One option for the separator is tosimply perform a gas-liquid separation to remove contaminants. Anotheroption is to use a separator such as a flash separator that can performa separation at a higher temperature.

Catalytic Dewaxing Process

The hydrotreated effluent 112 is then processed over one or morecatalyst beds containing a dewaxing catalyst in a catalytic dewaxingunit 120. Typically, the dewaxing catalyst is located in a beddownstream from any hydrotreatment catalyst stages and/or anyhydrotreatment catalyst present in a stage. This can allow the dewaxingto occur on molecules that have already been hydrotreated to remove asignificant fraction of organic sulfur- and nitrogen-containing species.

Suitable dewaxing catalysts can include molecular sieves such ascrystalline aluminosilicates (zeolites). In an embodiment, the molecularsieve can comprise, consist essentially of, or be a molecular sievehaving a structure with 10-member rings or smaller, such as ZSM-22,ZSM-23, ZSM-35 (or ferrierite), ZSM-48, or a combination thereof, forexample ZSM-23 and/or ZSM-48, or ZSM-48 and/or zeolite Beta. Optionallybut preferably, molecular sieves that are selective for dewaxing byisomerization as opposed to cracking can be used, such as ZSM-48,ZSM-23, or a combination thereof. Additionally or alternately, themolecular sieve can comprise, consist essentially of, or be a 10-memberring 1-D molecular sieve. Examples include EU-1, ZSM-35 (or ferrierite),ZSM-11, ZSM-57, NU-87, SAPO-11, ZSM-48, ZSM-23, and ZSM-22. Preferredmaterials are EU-2, EU-11, ZBM-30, ZSM-48, or ZSM-23. ZSM-48 is mostpreferred. Note that a zeolite having the ZSM-23 structure with a silicato alumina ratio of from 20:1 to 40:1 can sometimes be referred to asSSZ-32. Optionally but preferably, the dewaxing catalyst can include abinder for the molecular sieve, such as alumina, titania, silica,silica-alumina, zirconia, or a combination thereof, for example aluminaand/or titania or silica and/or zirconia and/or titania.

Preferably, the dewaxing catalysts used in processes according to thedisclosure are catalysts with a low ratio of silica to alumina. Forexample, for ZSM-48, the ratio of silica to alumina in the zeolite canbe less than 200:1, such as less than 110:1, or less than 100:1, or lessthan 90:1, or less than 75:1. In various embodiments, the ratio ofsilica to alumina can be from 50:1 to 200:1, such as 60:1 to 160:1, or70:1 to 100:1.

In various embodiments, the catalysts according to the disclosurefurther include a metal hydrogenation component. The metal hydrogenationcomponent is typically a Group VI and/or a Group VIII metal. Preferably,the metal hydrogenation component is a Group VIII noble metal.Preferably, the metal hydrogenation component is Pt, Pd, or a mixturethereof. In an alternative preferred embodiment, the metal hydrogenationcomponent can be a combination of a non-noble Group VIII metal with aGroup VI metal. Suitable combinations can include Ni, Co, or Fe with Moor W, preferably Ni with Mo or W.

The metal hydrogenation component may be added to the catalyst in anyconvenient manner. One technique for adding the metal hydrogenationcomponent is by incipient wetness. For example, after combining azeolite and a binder, the combined zeolite and binder can be extrudedinto catalyst particles. These catalyst particles can then be exposed toa solution containing a suitable metal precursor. Alternatively, metalcan be added to the catalyst by ion exchange, where a metal precursor isadded to a mixture of zeolite (or zeolite and binder) prior toextrusion.

The amount of metal in the catalyst can be at least 0.1 wt % based oncatalyst, or at least 0.15 wt %, or at least 0.2 wt %, or at least 0.25wt %, or at least 0.3 wt %, or at least 0.5 wt % based on catalyst. Theamount of metal in the catalyst can be 20 wt % or less based oncatalyst, or 10 wt % or less, or 5 wt % or less, or 2.5 wt % or less, or1 wt % or less. For embodiments where the metal is Pt, Pd, another GroupVIII noble metal, or a combination thereof, the amount of metal can befrom 0.1 to 5 wt %, preferably from 0.1 to 2 wt %, or 0.25 to 1.8 wt %,or 0.4 to 1.5 wt %. For embodiments where the metal is a combination ofa non-noble Group VIII metal with a Group VI metal, the combined amountof metal can be from 0.5 wt % to 20 wt %, or 1 wt % to 15 wt %, or 2.5wt % to 10 wt %.

The dewaxing catalysts useful in processes according to the disclosurecan also include a binder. In some embodiments, the dewaxing catalystsused in process according to the disclosure are formulated using a lowsurface area binder, where a low surface area binder represents a binderwith a surface area of 100 m²/g or less, or 80 m²/g or less, or 70 m²/gor less. The amount of zeolite in a catalyst formulated using a bindercan be from 30 wt % zeolite to 90 wt % zeolite relative to the combinedweight of binder and zeolite. Preferably, the amount of zeolite is atleast 50 wt % of the combined weight of zeolite and binder, such as atleast 60 wt % or from 65 wt % to 80 wt %.

A zeolite can be combined with binder in any convenient manner. Forexample, a bound catalyst can be produced by starting with powders ofboth the zeolite and binder, combining and mulling the powders withadded water to form a mixture, and then extruding the mixture to producea bound catalyst of a desired size. Extrusion aids can also be used tomodify the extrusion flow properties of the zeolite and binder mixture.The amount of framework alumina in the catalyst may range from 0.1 to3.33 wt %, or 0.1 to 2.7 wt %, or 0.2 to 2 wt %, or 0.3 to 1 wt %.

Process conditions in a catalytic dewaxing zone can include atemperature of from 200 to 450° C., preferably 270 to 400° C., ahydrogen partial pressure of from 1.8 MPag to 34.6 MPag (250 psig to5000 psig), preferably 4.8 MPag to 20.8 MPag, and a hydrogen circulationrate of from 35.6 m³/m³ (200 SCF/B) to 1781 m³/m³ (10,000 SCF/B),preferably 178 m³/m³ (1000 SCF/B) to 890.6 m³/m³ (5000 SCF/B). In stillother embodiments, the conditions can include temperatures in the rangeof 600° F. (343° C.) to 815° F. (435° C.), hydrogen partial pressures offrom 500 psig to 3000 psig (3.5 MPag-20.9 MPag), and hydrogen treat gasrates of from 213 m³/m³ to 1068 m³/m³ (1200 SCF/B to 6000 SCF/B). Theliquid hourly space velocity (LHSV) can be from 0.2 hr⁻¹ to 10 hr⁻¹,such as from 0.5 hr⁻¹ to 5 hr⁻¹ and/or from 1 hr⁻¹ to 4 hr⁻¹.

The dewaxed effluent 122 is separated by distillation in column 130 intoa naphtha product 132 having a boiling point range of less than about350° F. (176° C.), a diesel product 134 having a boiling point range ofabout 350° F. (176° C.) to about 700° F. (371° C.), and a Group III lubebase stock product 136 having a boiling point of greater than about 700°F. (371° C.). The naphtha product 132 has an octane value greater than60, preferably greater than 65, more preferably greater than 70, andideally greater than 75, allowing it to be directly blended intogasoline. The diesel product 134 has a T90 of between 650° F. (343° C.)and 700° F. (371° C.), a cloud point of less than 0° C., preferably lessthan −10° C., and more preferably less than −15° C., and qualifies as anultra-low sulfur diesel product. The base stock product 136 is of GroupIII quality, having a viscosity index of more than 120, less than 300ppm sulfur, and 10 wt % aromatics.

Hydrofinishing and/or Aromatic Saturation Process

In some aspects, the base stock product 136 is processed through ahydrofinishing and/or aromatic saturation stage 140. Hydrofinishingand/or aromatic saturation catalysts can include catalysts containingGroup VI metals, Group VIII metals, and mixtures thereof. In anembodiment, preferred metals include at least one metal sulfide having astrong hydrogenation function. In another embodiment, the hydrofinishingcatalyst can include a Group VIII noble metal, such as Pt, Pd, or acombination thereof. The mixture of metals may also be present as bulkmetal catalysts wherein the amount of metal is 30 wt % or greater basedon catalyst. Suitable metal oxide supports include low acidic oxidessuch as silica, alumina, silica-aluminas or titania, preferably alumina.The preferred hydrofinishing catalysts for aromatic saturation willcomprise at least one metal having relatively strong hydrogenationfunction on a porous support. Typical support materials includeamorphous or crystalline oxide materials such as alumina, silica, andsilica-alumina. The support materials may also be modified, such as byhalogenation, or in particular fluorination. The metal content of thecatalyst is often as high as 20 weight percent for non-noble metals. Inan embodiment, a preferred hydrofinishing catalyst can include acrystalline material belonging to the M41S class or family of catalysts.The M41S family of catalysts are mesoporous materials having high silicacontent. Examples include MCM-41, MCM-48 and MCM-50. A preferred memberof this class is MCM-41. If separate catalysts are used for aromaticsaturation and hydrofinishing, an aromatic saturation catalyst can beselected based on activity and/or selectivity for aromatic saturation,while a hydrofinishing catalyst can be selected based on activity forimproving product specifications, such as product color and polynucleararomatic reduction.

Hydrofinishing conditions can include temperatures from 125° C. to 425°C., preferably 180° C. to 280° C., a hydrogen partial pressure from 500psig (3.4 MPa) to 3000 psig (20.7 MPa), preferably 1500 psig (10.3 MPa)to 2500 psig (17.2 MPa), and liquid hourly space velocity from 0.1 hr⁻¹to 5 hr⁻¹ LHSV, preferably 0.5 hr⁻¹ to 1.5 hr⁻¹. Additionally, ahydrogen treat gas rate of from 35.6 m³/m³ to 1781 m³/m³ (200 SCF/B to10,000 SCF/B) can be used.

The hydrofinished base stock 142 is then stripped to remove lighthydrocarbons and separated in column 150 into two fractions—a lightneutral base stock 152 having a low viscosity of 2-8 cSt (at 100° C.),preferably 3-5 cSt (at 100° C.), and a heavy neutral base stock 154having a high viscosity of 6-30 cSt (at 100° C.), preferably 8-15 cSt(at 100° C.). Both Group III base stock fractions have a viscosity indexof greater than 120 and pour point of −15° C. and the cloud point-pourpoint spread is less than 30° C.

The inventive process provides several advantages over the typical baseoil production process. Whole petroleum crude with a high concentrationof waxy hydrocarbons can be efficiently upgraded to finished productswithout the difficulties waxy hydrocarbons generally present inprocessing. Because the waxy hydrocarbons are never concentrated, theneed for heated tanks and transport lines in the process is eliminated.The finished products can be obtained in essentially twostages—hydroprocessing and catalytic dewaxing. In the two stages, the350° F.−(176° C.−) molecules are upgraded by octane enhancement to aproduct high enough in octane to directly blend into gasoline. The 350°F.−650° F. (176-343° C.) distillate molecules are dewaxed, desulfurized,and hydrogenated into ultra-low sulfur diesel, and the 650° F.+(343°C.+) molecules are hydroisomerized and hydrogenated into Group III basestock. Further, the process minimizes distillation as no molecules arevaporized more than once and the high viscosity Group III base stockproduct is produced without vaporization.

The ability to simultaneously produce fuels and lubricants from a wholewaxy crude oil without significantly over- or under-converting somefraction of the feedstock is surprising. The yield and selectivitybenefits from processing whole waxy crude oil versus separatelyprocessing naphtha, distillate, and 650° F.+(343° C.+) fractions is alsosurprising. Without being bound by theory, it is believed that thestability and selectivity of the dewaxing catalyst described hereinenables such conversion and achieves a sufficiently flat pour pointversus boiling point profile to simultaneously upgrade naphtha range and1050° F.+(565° C.+) paraffins. Also, use of the described dewaxingcatalyst allows simultaneous production of low and high viscosity basestocks that meet or exceed Group III base stock specifications.Additionally, the 650° F.−(343° C.−) components of the feedstock reducemass transport limitations in the dewaxing catalyst and keep the yieldof C₃— paraffin molecules to less than 2 wt %. Less than 25 wt %,preferably less than 20 wt %, more preferably less than 15 wt %, andideally 10 wt % of the 650° F.+ lubricant range molecules are convertedinto 650° F.−(343° C.−) fuel range molecules.

EXAMPLE

Whole waxy crude oil having the properties listed below in Table 1 isprovided. The octane value of the 350° F.−(176° C.−) fraction of thewhole waxy crude oil is 40 and the cloud point of the 350-650° F.(176-343° C.) distillate fraction is 25° C.

TABLE 1 API 52 wt % H 14.6 wt % 200° F.+ 85 wt % 350° F.+ 40 wt % 650°F.+ 30 wt % 1050° F.+ 7 % aromatic carbon 6.8 ppm S 100 ppm N 134 wt %saturates 88 wt % aromatics 12 MCRT, wt % 0.25 Ni + V, ppm 1

The waxy crude oil is processed over a stacked bed of three commerciallyavailable nickel-molybdenum sulfided hydroprocessing catalysts at about1800 psig, about 0.4 hr⁻¹ LHSV, and about 340° C. start of cycletemperature. The yield of 650° F.+(343° C.+) product is about 28 wt %.The total liquid product has a sulfur content of <1 ppm and a nitrogencontent of <1 ppm. The hydroprocessed effluent is subjected to dewaxingover an alumina-bound ZSM-48 having a silica to alumina ratio of about70:1 with 0.6 wt % of platinum at about 0.675 LHSV, about 340° C., and1800 psig. The dewaxed effluent is distilled to produce a 1 wt % yieldof C₃— paraffins, 44 wt % C₄−350° F.+(176° C.+) gasoline with 73 octane,30 wt % yield of ULSD with a cetane of 60 and a cloud point of −20° C.,and a 25% yield of 650° F.+(343° C.+) base stocks.

The 650° F.+(343° C.+) base stocks is processed over an alumina boundMCM-41 catalyst with 0.3 wt % of palladium and 0.9 wt % of platinum atabout 1.0 hr⁻¹ LHSV, about 220° C., and 1800 psig, which producesnegligible 650° F.−(343° C.−) products. The hydrofinished 650° F.+(343°C.+) base stocks is distilled into two fractions—66 wt % of a 4 cSt (at100° C.) light neutral Group III base stock with a viscosity index of122 and a pour point of −40° F., and 34 wt % of a 8 cSt (at 100° C.)heavy neutral Group III base stock with a viscosity index of 128 and apour point of −20° F.

The inventive process yields 25 wt % of 650° F.+(343° C.+) Group IIIbase stock product—meaning 83% of the 650° F.+(343° C.+) molecules fromthe crude oil feedstock are retained. More than half of the 17%conversion of the 650° F.+(343° C.+) molecules to 650° F.−(343° C.−)molecules is caused by the boiling point lowering effect of paraffinisomerization (n-C₂₀ molecules converting to tri-methyl C₁₇ molecules)and aromatics saturation (naphthalenes with a C₆ to C₈ side-chainhydrogenating to decalins with no change in side-chain structure). Thereis a large improvement in the octane value of the 350° F.−(176° C.−)fraction, from an initial octane value of the feedstock of 40, making itunsuitable for blending into gasoline, to 73 in the product, which issuitable for blending into gasoline without further processing. The 350°F.−(176° C.−) fraction (naphtha) is also sulfur free. The 350° F.−650°F. (176-343° C.) distillate fraction is upgraded by reducing the pourpoint from +15° C. to −30° C. and the sulfur content from 100 ppm toless than 1 ppm, producing a premium quality ultra-low sulfur dieselblendstock.

All patents, test procedures, and other documents cited herein,including priority documents, are fully incorporated by reference to theextent such disclosure is not inconsistent and for all jurisdictions inwhich such incorporation is permitted.

While the illustrative forms disclosed herein have been described withparticularity, it will be understood that various other modificationswill be apparent to and can be readily made by those skilled in the artwithout departing from the spirit and scope of the disclosure.Accordingly, it is not intended that the scope of the claims appendedhereto be limited to the example and descriptions set forth herein, butrather that the claims be construed as encompassing all the features ofpatentable novelty which reside herein, including all features whichwould be treated as equivalents thereof by those skilled in the art towhich this disclosure pertains.

When numerical lower limits and numerical upper limits are listedherein, ranges from any lower limit to any upper limit are contemplated.

1. A method for producing lubricant base oils from a whole petroleumcrude oil, comprising: a. providing a whole petroleum crude oilfeedstock comprising less than about 2 wt % of heptane asphaltenes, lessthan about 2 wt % of Conradson carbon residue (CCR), and less than about50 ppm of metals; b. hydrotreating the whole petroleum crude oilfeedstock on at least one bed of a hydrotreating catalyst undereffective hydrotreating conditions to produce a hydrotreated effluenthaving less sulfur, nitrogen and aromatics than the whole petroleumcrude oil; c. dewaxing the hydrotreated effluent in the presence of adewaxing catalyst to produce a naphtha product having an octane valuegreater than 60, a diesel product having a cloud point less than 0° C.,and a lubricant base oil product; and d. fractionating the lubricantbase oil product into at least a low viscosity lubricant base oilproduct having a viscosity of 2-8 cSt at 100° C. and a high viscositylubricant base oil product having a viscosity of 6-30 cSt at 100° C. 2.The method of claim 1, wherein the low viscosity lubricant base oilproduct and the high viscosity lubricant base oil product have aviscosity index of at least 120, a pour point of about −15° C., and lessthan 300 ppm sulfur.
 3. The method of claim 1, wherein the naphthaproduct has an octane value of greater than
 70. 4. The method of claim1, wherein the diesel product comprises less than 15 ppm of sulfur and apour point of less than 0° C.
 5. The method of claim 1, wherein wholepetroleum crude oil feedstock comprises less than 0.5 wt % heptaneasphaltenes, less than 20 ppm sulfur and nitrogen, and less than 1 wt %carbonaceous residue.
 6. The method of claim 1, wherein at least twobeds of hydrotreating catalyst are used in step (b) and thehydrotreating catalyst comprises at least one Group VIII non-noble metaland at least one Group VI metal.
 7. The method of claim 6, wherein theGroup VIII non-noble metal is selected from Fe, Co, and/or Ni and theGroup VI metal is selected from Mo and/or W.
 8. The method of claim 1,wherein the hydrotreated effluent comprises less than 15 ppm sulfur,less than 5 ppm nitrogen, less than 2 wt % C₃— paraffins, and less than25 wt % of aromatics.
 9. The method of claim 1, wherein the dewaxingcatalyst of step (c) comprises ZSM-48 having a silica to alumina ratioof about 100:1 or less and 0.5-1.0 wt % of a Group VIII noble metal. 10.The method of claim 1, further comprising hydrofinishing the lubricantbase oil product prior to step (d) to remove polynuclear aromaticcompounds.
 11. The method of claim 1, wherein the low viscositylubricant base oil product has a viscosity of 3-5 cSt at 100° C. and thehigh viscosity lubricant base oil product has a viscosity of 8-15 cSt at100° C.
 12. A method for producing a naphtha product, a diesel product,and a lubricant base oil product from a whole petroleum crude oil,comprising: a. supplying a whole petroleum crude oil feedstock, withoutseparation or pretreatment, to a hydrotreating unit, wherein thefeedstock comprises less than about 2 wt % of heptane asphaltenes, lessthan about 2 wt % of Conradson carbon residue (CCR), and less than about50 ppm of metals; b. hydrotreating the whole petroleum crude oilfeedstock on at least one bed of a hydrotreating catalyst undereffective hydrotreating conditions to produce a hydrotreated effluenthaving less than 15 ppm sulfur, less than 5 ppm nitrogen, less than 2 wt% C₃— paraffins, and less than 25 wt % of aromatics; c. dewaxing thehydrotreated effluent in the presence of a dewaxing catalyst to producea dewaxed effluent; d. separating the dewaxed effluent into at least anaphtha product having an octane value greater than 60, a diesel producthaving a cloud point less than 0° C., and a base stock product; e.subjecting the base stock product to hydrofinishing and/or aromaticsaturation to remove polynuclear aromatic compounds and produce ahydrofinished base stock; and f. fractionating the hydrofinished basestock into at least a low viscosity lubricant base oil product having aviscosity of 2-8 cSt at 100° C. and a high viscosity lubricant base oilproduct having a viscosity of 6-30 cSt at 100° C.
 13. The method ofclaim 12, wherein the low viscosity lubricant base oil product and thehigh viscosity lubricant base oil product have a viscosity index of atleast 120, a pour point of about −15° C., and less than 300 ppm sulfur.14. The method of claim 12, wherein the low viscosity lubricant base oilproduct has a viscosity of 3-5 cSt at 100° C. and the high viscositylubricant base oil product has a viscosity of 8-15 cSt at 100° C. 15.The method of claim 12, wherein the naphtha product has an octane valueof greater than
 70. 16. The method of claim 12, wherein the dieselproduct comprises less than 15 ppm of sulfur and a pour point of lessthan 0° C.
 17. The method of claim 12, wherein whole petroleum crude oilfeedstock comprises less than 0.5 wt % heptane asphaltenes, less than 20ppm sulfur and nitrogen, and less than 1 wt % carbonaceous residue. 18.The method of claim 12, wherein at least two beds of hydrotreatingcatalyst are used in step (b) and the hydrotreating catalyst comprisesat least one Group VIII non-noble metal and at least one Group VI metal.19. The method of claim 18, wherein the Group VIII non-noble metal isselected from Fe, Co, and/or Ni and the Group VI metal is selected fromMo and/or W.
 20. The method of claim 12, wherein the dewaxing catalystof step (c) comprises ZSM-48 having a silica to alumina ratio of about100:1 or less and 0.5-1.0 wt % of a Group VIII noble metal.